The Paleoproterozoic Kolvitsa Anorthosite Massif: New Data on the U–Pb Age (ID TIMS) and Geochemical Features of Zircon     

Steshenko  E. N.  Nikolaev  A. I.  Bayanova  T. B.  Drogobuzhskaya  S. V.  Chashchin  V. V.  Serov  P. A.  Lyalina  L. M.  Novikov  A. I.  Elizarov  D. V. 《Doklady Earth Sciences》2018,479(1):366-370

Doklady Earth Sciences - The rocks and minerals of the Kolvitsa massif are studied by complex isotopic–geochronological and geochemical (U–Pb, Sm–Nd, REE contents of zircons)...  相似文献   

Observations of Near-Earth Optical Transients with the Lomonosov Space Observatory     

V. M. Lipunov  E. S. Gorbovskoy  V. G. Kornilov  V. V. Chazov  M. I. Panasyuk  S. I. Svertilov  I. V. Yashin  V. L. Petrov  V. V. Kallegaev  A. A. Amelushkin  D. M. Vlasenko 《Astronomy Reports》2018,62(7):426-435

The results of observations with the MASTER-SHOK robotic wide-field optical cameras onboard the Lomonosov Space Observatory carried out in 2016 are presented. In all, the automated transient detection system transmitted 22 181 images of moving objects with signal-to-noise ratios greater than 5 to the Earth. Approximately 84% of these images are identified with well-known artificial Earth satellites (including repeated images of the same satellite) and fragments of such satellites (space debris), according to databases of known satellites. The remaining 16% of the images are relate to uncatalogued objects. This first experience in optical space-based monitoring of near-Earth space demonstrates the high efficiency and great potential of using large-aperture cameras in space, based on the software and technology of the MASTER robotic optical complexes (the Mobile Astronomical System of TElescope- Robots (MASTER) global network of robotic telescopes of Lomonosov Moscow State University).  相似文献   

The Role of Pressure as a Source of Gravity and Wormholes     

I. D. Novikov  D. I. Novikov  N. S. Kardashev 《Astronomy Reports》2018,62(7):421-425

The role of pressure as a source of gravity in general relativity is considered. In homogeneous, anisotropic cosmological models, the anisotropic pressure components along different coordinate axes are included as terms in the equations determining the accelerations along these axes; in this sense, this situation is similar to how the mass density is included in these equations. A change in the pressure component along one of the coordinates leads to an anisotropic change in the accelerations along all three coordinates. However, the pressure components are not present in the equation determining the initial conditions. On the other hand, with an inhomogeneous matter density distribution, the mass density and pressure play fundamentally different roles as sources of gravity. The consequences of this are considered.  相似文献   

Diagnostic of a Solar Flare via Analyses of Emission in Spectral Lines of Highly Ionized Iron     

I. M. Podgorny  A. I. Podgorny 《Astronomy Reports》2018,62(10):696-704

An analysis of the dynamics of the electron temperature of the solar atmosphere in regions where solar flares appear is presented. The temperatures are estimated from the emission in spectral lines of ions with various degrees of ionization. The emission of ionized helium and highly ionized iron was used. Images of preflare states and of flares from the archive of the American SDO spacecraft are analyzed. A solar flare is usually preceded by the registration of a bright glowing structure above the action region, with a temperature exceeding that of the corona. This preflare structure (~10¹⁰ cm) is identified with the development of a system of currents, which, according to numerical simulations, is responsible for the accumulation of energy above the active region before the flare. After several tens of hours of a slow increase in the brightness of the preflare glow in the 94 Å iron (FeXVIII) line, the emission in the 193 Å line of FeXXIV increases sharply, indicating a flare-like growth of the temperature up to at least 20 MK. This growth of the emission coincides with the onset of the solar flare. The observed dynamics of the emission in spectral lines of highly ionized ions is consistent with an electrodynamic model of a solar flare based on the accumulation of magnetic energy in a current sheet above the active region and the explosive release of the stored energy. Studies of mechanisms for solar flares are of special importance in connection with the discovery of solar cosmic rays. Information from the worldwide network of neutron monitors and from the GOES spacecraft has made it possible to firmly state that the source of solar rays is solar flares, not shocks generated by such flares. It cannot be ruled out that a similar mechanism, not shocks, is also responsible for the acceleration of cosmic rays in the Galaxy.  相似文献   

The Spots and Activity of Stars in the Beehive Cluster Observed by the Kepler Space Telescope (K2)     

I. S. Savanov  E. S. Kalinicheva  E. S. Dmitrienko 《Astronomy Reports》2018,62(5):352-358

The spottedness parameters S (the fraction of the visible surface of the star occupied by spots) characterizing the activity of 674 stars in the Beehive Cluster (age 650 Myr) are estimated, together with variations of this parameter as a function of the rotation period, Rossby number Ro and other characteristics of the stars. The activity of the stars in this cluster is lower than the activity of stars in the younger Pleiades (125 Myr). The average S value for the Beehive Cluster stars is 0.014, while Pleiades stars have the much higher average value 0.052. The activity parameters of 61 solar-type stars in the Beehive Cluster, similar Hyades stars (of about the same age), and stars in the younger Pleiades are compared. The average S value of such objects in the Beehive Cluster is 0.014± 0.008, nearly coincident with the estimate obtained for solar-type Hyades stars. The rotation periods of these objects are 9.1 ± 3.4 day, on average, in agreement with the average rotation period of the Hyades stars (8.6 ^d ). Stars with periods exceeding 3–4 ^d are more numerous in the Beehive Cluster than in the Pleiades, and their periods have a larger range, 3–30 ^d . The characteristic dependence with a kink at Ro (saturation) = 0.13 is not observed in the S–Rossby number diagram for the Beehive and Hyades stars, only a clump of objects with Rossby numbers Ro > 0.7. The spottedness data for the Beehive Cluster and Hyades stars are in good agreement with the S values for dwarfs with ages of 600–700 Myr. This provides evidence for the reliability of the results of gyrochronological calibrations. The data for the Beehive and Pleiades stars are used to analyze variations in the spot-forming activity for a large number of stars of the same age that are members of a single cluster. A joint consideration of the data for two clusters can be used to draw conclusions about the time evolution of the activity of stars of different masses (over a time interval of the order of 500 Myr).  相似文献   

Ya.B. Zeldovich and Foundation of the Accretion Theory     

N. I. Shakura 《Astronomy Reports》2018,62(12):823-833

This brief review is dedicated to academician Yakov Borisovich Zeldovich, the science of his epoch and the creation of modern accretion theory.  相似文献   

Recognition of Strong Earthquake Prone Areas in the Altai–Sayan–Baikal Region     

Gorshkov  A. I.  Soloviev  A. A.  Zharkikh  Ju. I. 《Doklady Earth Sciences》2018,479(1):412-414

The locations of areas prone to strong earthquakes (M ≥ 6.0) in the Altai–Sayan–Baikal region are determined. Based on a scheme of morphostructural zoning of the region and by using the CORA-3 pattern recognition algorithm, all intersections of morphostructural lineaments are separated into two classes: the highly seismic intersections in the vicinities of which strong earthquakes can occur and low seismic in the vicinities of which only earthquakes with M < 6.0 are possible. Recognition was performed for the vectors the components of which were measured values of the geological–geophysical characteristics describing the respective intersection. The result obtained allows the zones of high seismic hazard to be identified more reliably in the region.

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Geochemical Features of Cupriferous Sandstones in the Orenburg Area of the Ural Region     

Volkov  A. V.  Novikov  I. A.  Razumovskiy  A. A.  Murashov  K. Yu.  Sidorova  N. V.  Sidorov  A. A. 《Doklady Earth Sciences》2018,479(1):393-396

The new geochemical data obtained of cupriferous sandstones of the Orenburg area of the Ural region show that the Permian host stratum could have served as the source of rare-earth elements and other microelements for the ore-forming fluids. They confirm the possibility of using a convection model to explain the genesis of the copper ores studied. This model indicates the likely multistage development of mineralization to significant depths, like in the Manto deposits in Chili. Consequently, the Permian cupriferous sandstones of the southwestern area of the Ural region can be considered a very promising source of raw material for the development of copper industry in the area.

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Electroconducting Elements of the Ultradeep Fluid–Fault Systems as Indicators of Seismically Active Zones of the Eastern Margin of the Eurasian Continent: Evidence from Magnetotelluric Data     

Nikiforov  V. M.  Shkabarnya  G. N.  Kaplun  V. B.  Zhukovin  A. Yu.  Varentsov  I. M.  Palshin  N. A.  Cuong  D. H.  Trung  N. N.  Hung  D. Q. 《Doklady Earth Sciences》2018,480(2):831-838

Doklady Earth Sciences - A fundamentally new conclusion that zones of high seismic activity are controlled by electroconducting (fluid-saturated) fragments rather than by the entire deep fault is...  相似文献   

Genesis of Diamond in Metal–Carbon and Metal–Sulfur–Carbon Melts: Evidence from Experimental Data     

Zhimulev  E. I.  Chepurov  A. I.  Sobolev  N. V. 《Doklady Earth Sciences》2018,483(1):1473-1474

Doklady Earth Sciences - The experimental data on diamond growth in the Fe–Ni–S–C and Fe–S–C systems with a sulfur content of 5–14 wt % at 5.5 GPa and...  相似文献